Conjunctival expression of thymosin-β4 in vernalkeratoconjunctivitis

[摘要] Purpose: Thymosin-β4 (Tβ4) is a small actin-sequestratingpeptide that modulates inflammation and healing in different tissues.The aim of this study was to investigate the molecular and biochemicalexpression of Tβ4 in the healthy conjunctiva and in the conjunctivaof patients with vernal keratoconjunctivitis (VKC), a severe allergiceye disease characterized by chronic inflammation and marked tissueremodeling.Methods: Conjunctival tissues, obtained from seven VKC patients andfive sex/age-matched healthy subjects, were evaluated for Tβ4expression by relative real time-PCR and light/confocal microscopy. Thedistribution patterns of Tβ4 in conjunctival sections as well asTβ4 expression by mast cells (AA1), eosinophils (EG2), andfibroblast/myofibroblasts (Thy1/α-SMA) in VKC tissues was alsoevaluated by double immunofluorescence.Results: Compared to healthy specimens, Tβ4 mRNA appearedupregulated in VKC conjunctival biopsies as detected by real-time PCR.In the healthy conjunctiva, Tβ4 protein expression was confined tothe conjunctival epithelium, while a weak staining was observed in thestroma. In VKC conjunctival sections, Tβ4 immunoreactivity wasselectively increased in the stroma where, by confocal analysis of VKCpapillary formations, Tβ4 appeared to be mostly localized ineosinophils and activated fibroblasts/myofibroblasts.Conclusions: Our data provides the first evidence of Tβ4expression in the conjunctival tissues. The upregulation of both Tβ4 mRNA and protein in the conjunctival stroma, and its peculiarlocalization in eosinophils and myofibroblasts populating VKC lesions,suggest a possible role for Tβ4 in tissue inflammation andremodeling occurring in VKC.

[学科分类] 生物化学/生物物理